@article{cristescu_popescu_dorcioman_miroiu_socol_mihailescu_gittard_miller_narayan_enculescu_et al._2013, title={Antimicrobial activity of biopolymer-antibiotic thin films fabricated by advanced pulsed laser methods}, volume={278}, ISSN={["0169-4332"]}, DOI={10.1016/j.apsusc.2013.01.062}, abstractNote={Abstract We report on thin film deposition by matrix assisted pulsed laser evaporation (MAPLE) of two polymer–drug composite thin film systems. A pulsed KrF* excimer laser source ( λ  = 248 nm, τ  = 25 ns, ν  = 10 Hz) was used to deposit composite thin films of poly( d , l -lactide) (PDLLA) containing several gentamicin concentrations. FTIR spectroscopy was used to demonstrate that MAPLE-transferred materials exhibited chemical structures similar to those of drop cast materials. Scanning electron microscopy data indicated that MAPLE may be used to fabricate thin films of good morphological quality. The activity of PDLLA–gentamicin composite thin films against Staphylococcus aureus bacteria was demonstrated using drop testing. The influence of drug concentration on microbial viability was also assessed. Our studies indicate that polymer–drug composite thin films prepared by MAPLE may be used to impart antimicrobial activity to implants, medical devices, and other contact surfaces.}, journal={APPLIED SURFACE SCIENCE}, author={Cristescu, R. and Popescu, C. and Dorcioman, G. and Miroiu, F. M. and Socol, G. and Mihailescu, I. N. and Gittard, S. D. and Miller, P. R. and Narayan, R. J. and Enculescu, M. and et al.}, year={2013}, month={Aug}, pages={211–213} }
 @article{gittard_chen_xu_ovsianikov_chichkov_monteiro-riviere_narayan_2013, title={The effects of geometry on skin penetration and failure of polymer microneedles}, volume={27}, ISSN={["1568-5616"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84874631649&partnerID=MN8TOARS}, DOI={10.1080/01694243.2012.705101}, abstractNote={Microneedles are small-scale devices that may be used for drug delivery and biosensing. In this study, the forces required for mechanical failure, the modes of mechanical failure, as well as the mechanisms for microneedle penetration into porcine skin were examined. Microneedles produced from the acrylate-based polymer e-Shell 200 using an indirect rapid prototyping approach involving two-photon polymerization and poly(dimethylsiloxane) micromolding were found to possess sufficient strength for penetration of porcine skin. The failure forces were an order of magnitude greater than the forces necessary for full insertion into the skin. Bending was the most common form of failure; an increasing aspect ratio and a decreasing tip diameter were associated with lower failure forces. Video captured during skin penetration revealed that microneedle penetration into the skin occurred by means of a series of insertions and not by means of a single insertion event. Images obtained during and after skin penetration confirmed microneedle penetration of skin as well as transdermal delivery of lucifer yellow dye. These findings shed insight into the mechanisms of microneedle penetration and failure, facilitating design improvements for polymer microneedles.}, number={3}, journal={JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY}, author={Gittard, Shaun D. and Chen, Bo and Xu, Huadong and Ovsianikov, Aleksandr and Chichkov, Boris N. and Monteiro-Riviere, Nancy A. and Narayan, Roger J.}, year={2013}, month={Feb}, pages={227–243} }
 @article{cristescu_popescu_socol_visan_mihailescu_gittard_miller_martin_narayan_andronie_et al._2011, title={Deposition of antibacterial of poly(1,3-bis-(p-carboxyphenoxy propane)-co-(sebacic anhydride)) 20:80/gentamicin sulfate composite coatings by MAPLE}, volume={257}, ISSN={["1873-5584"]}, DOI={10.1016/j.apsusc.2010.11.141}, abstractNote={We report on thin film deposition of poly(1,3-bis-(p-carboxyphenoxy propane)-co-sebacic anhydride)) 20:80 thin films containing several gentamicin concentrations by matrix assisted pulsed laser evaporation (MAPLE). A pulsed KrF* excimer laser was used to deposit the polymer–drug composite thin films. Release of gentamicin from these MAPLE-deposited polymer conjugate structures was assessed. Fourier transform infrared spectroscopy was used to demonstrate that the functional groups of the MAPLE-transferred materials were not changed by the deposition process nor were new functional groups formed. Scanning electron microscopy confirmed that MAPLE may be used to fabricate thin films of good morphological quality. The activity of gentamicin-doped films against Escherichia coli and Staphylococcus aureus bacteria was demonstrated using disk diffusion and antibacterial drop test. Our studies indicate that deposition of polymer–drug composite thin films prepared by MAPLE is a suitable technique for performing controlled drug delivery. Antimicrobial thin film coatings have several medical applications, including use for indwelling catheters and implanted medical devices.}, number={12}, journal={APPLIED SURFACE SCIENCE}, author={Cristescu, R. and Popescu, C. and Socol, G. and Visan, A. and Mihailescu, I. N. and Gittard, S. D. and Miller, P. R. and Martin, T. N. and Narayan, R. J. and Andronie, A. and et al.}, year={2011}, month={Apr}, pages={5287–5292} }
 @article{gittard_miller_jin_martin_boehm_chisholm_stafslien_daniels_cilz_monteiro-riviere_et al._2011, title={Deposition of antimicrobial coatings on microstereolithography-fabricated microneedles}, volume={63}, ISSN={["1543-1851"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000291610800011&KeyUID=WOS:000291610800011}, DOI={10.1007/s11837-011-0093-3}, number={6}, journal={JOM}, author={Gittard, Shaun D. and Miller, Philip R. and Jin, Chunming and Martin, Timothy N. and Boehm, Ryan D. and Chisholm, Bret J. and Stafslien, Shane J. and Daniels, Justin W. and Cilz, Nicholas and Monteiro-Riviere, Nancy A. and et al.}, year={2011}, month={Jun}, pages={59–68} }
 @article{gittard_miller_boehm_ovsianikov_chichkov_heiser_gordon_monteiro-riviere_narayan_2011, title={Multiphoton microscopy of transdermal quantum dot delivery using two photon polymerization-fabricated polymer microneedles}, volume={149}, ISSN={["1364-5498"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000285924900015&KeyUID=WOS:000285924900015}, DOI={10.1039/c005374k}, abstractNote={Due to their ability to serve as fluorophores and drug delivery vehicles, quantum dots are a powerful tool for theranostics-based clinical applications. In this study, microneedle devices for transdermal drug delivery were fabricated by means of two-photon polymerization of an acrylate-based polymer. We examined proliferation of cells on this polymer using neonatal human epidermal keratinocytes and human dermal fibroblasts. The microneedle device was used to inject quantum dots into porcine skin; imaging of the quantum dots was performed using multiphoton microscopy.}, journal={FARADAY DISCUSSIONS}, author={Gittard, Shaun D. and Miller, Philip R. and Boehm, Ryan D. and Ovsianikov, Aleksandr and Chichkov, Boris N. and Heiser, Jeremy and Gordon, John and Monteiro-Riviere, Nancy A. and Narayan, Roger J.}, year={2011}, pages={171–185} }
 @article{ovsianikov_malinauskas_schlie_chichkov_gittard_narayan_loebler_sternberg_schmitz_haverich_2011, title={Three-dimensional laser micro- and nano-structuring of acrylated poly(ethylene glycol) materials and evaluation of their cytoxicity for tissue engineering applications}, volume={7}, ISSN={["1878-7568"]}, DOI={10.1016/j.actbio.2010.10.023}, abstractNote={The natural cell environment is characterized by complex three-dimensional structures, which contain features at multiple length scales. Many in vitro studies of cell behavior in three dimensions rely on the availability of artificial scaffolds with controlled three-dimensional topologies. In this paper, we demonstrate fabrication of three-dimensional scaffolds for tissue engineering out of poly(ethylene glycol) diacrylate (PEGda) materials by means of two-photon polymerization (2PP). This laser nanostructuring approach offers unique possibilities for rapid manufacturing of three-dimensional structures with arbitrary geometries. The spatial resolution dependence on the applied irradiation parameters is investigated for two PEGda formulations, which are characterized by molecular weights of 302 and 742. We demonstrate that minimum feature sizes of 200nm are obtained in both materials. In addition, an extensive study of the cytotoxicity of the material formulations with respect to photoinitiator type and photoinitiator concentration is undertaken. Aqueous extracts from photopolymerized PEGda samples indicate the presence of water-soluble molecules, which are toxic to fibroblasts. It is shown that sample aging in aqueous medium reduces the cytotoxicity of these extracts; this mechanism provides a route for biomedical applications of structures generated by 2PP microfabrication and photopolymerization technologies in general. Finally, a fully biocompatible combination of PEGda and a photoinitiator is identified. Fabrication of reproducible scaffold structures is very important for systematic investigation of cellular processes in three dimensions and for better understanding of in vitro tissue formation. The results of this work suggest that 2PP may be used to polymerize poly(ethylene glycol)-based materials into three-dimensional structures with well-defined geometries that mimic the physical and biological properties of native cell environments.}, number={3}, journal={ACTA BIOMATERIALIA}, author={Ovsianikov, A. and Malinauskas, M. and Schlie, S. and Chichkov, B. and Gittard, S. and Narayan, R. and Loebler, M. and Sternberg, K. and Schmitz, K. -P. and Haverich, A.}, year={2011}, month={Mar}, pages={967–974} }
 @article{lewis_gittard_narayan_berry_brigmon_ramamurti_singh_2010, title={Assessment of microbial biofilm growth on nanocrystalline diamond in a continuous perfusion environment}, volume={132}, number={3}, journal={Journal of Manufacturing Science and Engineering}, author={Lewis, J. S. and Gittard, S. D. and Narayan, R. J. and Berry, C. J. and Brigmon, R. L. and Ramamurti, R. and Singh, R. N.}, year={2010} }
 @article{doraiswamy_ovsianikov_gittard_monteiro-riviere_crombez_montalvo_shen_chichkov_narayan_2010, title={Fabrication of Microneedles Using Two Photon Polymerization for Transdermal Delivery of Nanomaterials}, volume={10}, ISSN={["1533-4899"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000280361400003&KeyUID=WOS:000280361400003}, DOI={10.1166/jnn.2010.2636}, abstractNote={Microneedle devices for transdermal delivery of nanoscale pharmacologic agents were fabricated out of organically-modified ceramic (Ormocer) materials using two photon polymerization. Out-of-plane hollow microneedle arrays with various aspect ratios were fabricated using this rapid prototyping process. Human epidermal keratinocyte (HEK) viability on Ormocer surfaces fabricated using two photon polymerization was similar to that on control surfaces. Nanoindentation studies were performed to determine hardness and Young's modulus values for Ormocer materials. Microneedies were shown to enable more rapid distribution of the PEG-amine quantum dot solution to the deep epidermis and dermis layers of porcine skin than topical administration. Our results suggest that two photon polymerization may be used to create microneedle arrays for transdermal delivery of nanoscale pharmacologic agents.}, number={10}, journal={JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY}, author={Doraiswamy, Anand and Ovsianikov, Aleksandr and Gittard, Shaun D. and Monteiro-Riviere, Nancy A. and Crombez, Rene and Montalvo, Eva and Shen, Weidian and Chichkov, Boris N. and Narayan, Roger J.}, year={2010}, month={Oct}, pages={6305–6312} }
 @article{koroleva_schlie_fadeeva_gittard_miller_ovsianikov_koch_narayan_chichkov_2010, title={Microreplication of laser-fabricated surface and three-dimensional structures}, volume={12}, ISSN={["2040-8986"]}, DOI={10.1088/2040-8978/12/12/124009}, abstractNote={The fabrication of defined surface topographies and three-dimensional structures is a challenging process for various applications, e.g. in photonics and biomedicine. Laser-based technologies provide a promising approach for the production of such structures. The advantages of femtosecond laser ablation and two-photon polymerization for microstructuring are well known. However, these methods cannot be applied to all materials and are limited by their high cost and long production time. In this study, biomedical applications of an indirect rapid prototyping, molding microreplication of laser-fabricated two- and three-dimensional structures are examined. We demonstrate that by this method any laser-generated surface topography as well as three-dimensional structures can be replicated in various materials without losing the original geometry. The replication into multiple copies enables fast and perfect reproducibility of original microstructures for investigations of cell–surface interactions. Compared to unstructured materials, we observe that microstructures have strong influence on morphology and localization of fibroblasts, whereas neuroblastoma cells are not negatively affected.}, number={12}, journal={JOURNAL OF OPTICS}, author={Koroleva, Anastasia and Schlie, Sabrina and Fadeeva, Elena and Gittard, Shaun D. and Miller, Philip and Ovsianikov, Aleksandr and Koch, Juergen and Narayan, Roger J. and Chichkov, Boris N.}, year={2010}, month={Dec} }
 @article{gittard_pierson_ha_wu_narayan_robinson_2010, title={Supercapacitive transport of pharmacologic agents using nanoporous gold electrodes}, volume={5}, ISSN={["1860-7314"]}, DOI={10.1002/biot.200900250}, abstractNote={Abstract}, number={2}, journal={BIOTECHNOLOGY JOURNAL}, author={Gittard, Shaun D. and Pierson, Bonnie E. and Ha, Cindy M. and Wu, Chung-An Max and Narayan, Roger J. and Robinson, David B.}, year={2010}, month={Feb}, pages={192–200} }
 @article{gittard_ovsianikov_akar_chichkov_monteiro-riviere_stafslien_chisholm_shin_shih_lin_et al._2010, title={Two Photon Polymerization-Micromolding of Polyethylene Glycol-Gentamicin Sulfate Microneedles}, volume={12}, ISSN={["1438-1656"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000277655500011&KeyUID=WOS:000277655500011}, DOI={10.1002/adem.200980012}, abstractNote={Abstract}, number={4}, journal={ADVANCED ENGINEERING MATERIALS}, author={Gittard, Shaun D. and Ovsianikov, Aleksandr and Akar, Hasan and Chichkov, Boris and Monteiro-Riviere, Nancy A. and Stafslien, Shane and Chisholm, Bret and Shin, Chun-Che and Shih, Chun-Ming and Lin, Shing-Jong and et al.}, year={2010}, month={Apr}, pages={B77–B82} }
 @article{gittard_hojo_hyde_scarel_narayan_parsons_2009, title={Antifungal Textiles Formed Using Silver Deposition in Supercritical Carbon Dioxide}, volume={19}, ISSN={1059-9495 1544-1024}, url={http://dx.doi.org/10.1007/s11665-009-9514-7}, DOI={10.1007/s11665-009-9514-7}, number={3}, journal={Journal of Materials Engineering and Performance}, publisher={Springer Science and Business Media LLC}, author={Gittard, Shaun D. and Hojo, Daisuke and Hyde, G. Kevin and Scarel, Giovanna and Narayan, Roger J. and Parsons, Gregory N.}, year={2009}, month={Jul}, pages={368–373} }
 @article{gittard_perfect_monteiro-riviere_wei_jin_narayan_2009, title={Assessing the antimicrobial activity of zinc oxide thin films using disk diffusion and biofilm reactor}, volume={255}, ISSN={["1873-5584"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000263893800027&KeyUID=WOS:000263893800027}, DOI={10.1016/j.apsusc.2009.01.009}, abstractNote={The electronic and chemical properties of semiconductor materials may be useful in preventing growth of microorganisms. In this article, in vitro methods for assessing microbial growth on semiconductor materials will be presented. The structural and biological properties of silicon wafers coated with zinc oxide thin films were evaluated using atomic force microscopy, X-ray photoelectron spectroscopy, and MTT viability assay. The antimicrobial properties of zinc oxide thin films were established using disk diffusion and CDC Biofilm Reactor studies. Our results suggest that zinc oxide and other semiconductor materials may play a leading role in providing antimicrobial functionality to the next-generation medical devices.}, number={11}, journal={APPLIED SURFACE SCIENCE}, author={Gittard, Shaun D. and Perfect, John R. and Monteiro-Riviere, Nancy A. and Wei, Wei and Jin, Chunming and Narayan, Roger J.}, year={2009}, month={Mar}, pages={5806–5811} }
 @article{gittard_narayan_jin_ovsianikov_chichkov_monteiro-riviere_stafslien_chisholm_2009, title={Pulsed laser deposition of antimicrobial silver coating on Ormocer (R) microneedles}, volume={1}, ISSN={["1758-5090"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000278118300001&KeyUID=WOS:000278118300001}, DOI={10.1088/1758-5082/1/4/041001}, abstractNote={One promising option for transdermal delivery of protein- and nucleic acid-based pharmacologic agents involves the use of microneedles. However, microneedle-generated pores may allow microorganisms to penetrate the stratum corneum layer of the epidermis and cause local or systemic infection. In this study, microneedles with antimicrobial functionality were fabricated using two-photon polymerization–micromolding and pulsed laser deposition. The antibacterial activity of the silver-coated organically modified ceramic (Ormocer®) microneedles was demonstrated using an agar diffusion assay. Human epidermal keratinocyte viability on the Ormocer® surfaces coated with silver was similar to that on uncoated Ormocer® surfaces. This study indicates that coating microneedles with silver thin films using pulsed laser deposition is a useful and novel approach for creating microneedles with antimicrobial functionality.}, number={4}, journal={BIOFABRICATION}, author={Gittard, S. D. and Narayan, R. J. and Jin, C. and Ovsianikov, A. and Chichkov, B. N. and Monteiro-Riviere, N. A. and Stafslien, S. and Chisholm, B.}, year={2009}, month={Dec} }
 @misc{gittard_narayan, title={Laser direct writing of micro- and nano-scale medical devices}, volume={7}, number={3}, journal={Expert Review of Medical Devices}, author={Gittard, S. D. and Narayan, R.}, pages={343–356} }
 @misc{gittard_ovsianikov_chichkov_doraiswamy_narayan, title={Two-photon polymerization of microneedles for transdermal drug delivery}, volume={7}, number={4}, journal={Expert Opinion on Drug Delivery}, author={Gittard, S. D. and Ovsianikov, A. and Chichkov, B. N. and Doraiswamy, A. and Narayan, R. J.}, pages={513–533} }